The invention is concerned with liquid oral prebrushing compositions containing pyrophosphates and sodium lauryl sulfate for removal of plaque before brushing with a dentifrice.
Dental plaque is present to some degree, in the form of a film, on virtually all dental surfaces. It is a byproduct of microbial growth, and comprises a dense microbial layer consisting of a mass of microorganisms embedded in a polysaccharide matrix. The microorganisms present in plaque are mainly coccoidal organisms, particularly in early plaque, which, in the mouths of some persons at least, change to filamentous organisms after a few days. Plaque itself adheres firmly to dental surfaces and is removed only with difficulty even through a rigorous brushing regimen. Moreover, plaque rapidly reforms on the tooth surface after it is removed.
Plaque may form on any part of the tooth surfaces, and is found particularly at the gingival margin, in pits and fissures in the enamel, and on the surface of dental calculus. As discussed in greater detail below, the danger associated with the formation of plaque on the teeth lies in the tendency of plaque to build up and eventually contribute to gingivitis, periodontitis and other types of periodontal disease, as well as dental caries and dental calculus.
More specifically, dental plaque is a precursor to the formation of the hard crystalline buildup on teeth referred to as dental calculus. Both the bacterial and the nonbacterial components of plaque mineralize to form calculus, which comprises mineralized bacteria as well as organic constituents, such as epithelial cells, live bacteria, salivary proteins, leucocytes, and crystals of substances having molecularly bound calcium and phosphorus, e.g., hydroxyapatite, 3[Ca.sub.3 (PO.sub.4).sub.2 ]Ca(OH).sub.2, octacalcium phosphate, Ca.sub.8 (HPO.sub.4).sub.2 (PO.sub.4).sub.4 5H.sub.2 O, brushite, CaHPO.sub.4-2 H.sub.2 O, and whitlockite, which is considered to have the formula beta-Ca.sub.3 (PO.sub.4).sub.2. Dental plaque and, hence, calculus are particularly prone to form at the gingival margin, i.e., the junction of the tooth and gingiva. The buildup of plaque at the gingival margin is believed to be the prime cause of gingivitis and other periodontal disorders.
Regular tooth brushing with a conventional dentifrice for some persons greatly retards or even prevents the accumulation of significant amounts of plaque and calculus. For other persons, however, plaque builds up rapidly even with regular brushing, which, in turn, leads to the formation of calculus, caries, and presents the danger of periodontal diseases. It is widely recognized in dentistry that a rigorous brushing regimen alone for many individuals will not prevent the formation of significant amounts of plaque.
Mouthwashes are employed in conventional regimens of oral hygiene. Conventional mouthwashes serve primarily to sweeten the breath, are formulated for that purpose, and are believed not to function in any significant way to loosen or remove plaque from the dental surfaces. Since the user typically does not employ a conventional mouthwash expressly for the purpose of cleansing the teeth of plaque, mouthwashes are not routinely used immediately prior to brushing as a way of rendering plaque more amenable to removal during the subsequent brushing process. The present prebrushing compositions of the invention instead are used immediately before brushing.
Liquid oral compositions, such as mouthrinses and mouthwashes, containing sodium lauryl sulfate as a surface active agent are known, e.g. as described in U.S. Pat. No. 4,666,708 which is incorporated herein by reference.
Pyrophosphate salts have been used for their anticalculus properties in toothpastes and mouthwashes according to U.S. Pat. Nos. 4,590,066 and 4,684,518.